Four years ago the state promised to provide $2.9 billion in tax credits to help upgrade Michigan auto plants. Now, while few are saying the deals were a bad idea the sense of celebration is long gone. The bill for the job rescue — and similar ones in other states that used tax credits aggressively — is now coming due and providing a lesson in the downside of such measures.

Apple CEO Tim Cook took the stage at the company's annual shareholders meeting this week amid record sales and a soaring stock price. But that wasn't on the minds of a pair of investors however, instead they inquired about the possibility of the tech giant acquiring electric car manufacturer Tesla.

Four trains hauling crude oil have derailed in the U.S. and Canada since mid-February. The derailments have deepened safety concerns that if an oil-train accident were to occur in a populated area, the results could be disastrous.